In the past, there has been proposed a switching apparatus for operating light emitting diodes (LEDs) (e.g., Document 1 [JP 2004-536434 A]).
The switching apparatus of Document 1 includes a single ended primary inductance converter (SEPIC).
For power supply devices such as the switching apparatus disclosed in Document 1, there is a demand that the power supply device is downsized but nevertheless a decrease in an efficiency of power transfer is suppressed.